Drywall clips
Regarding a new 1 1/2 story home in a hot humid climate (2B), 2-stud corners at outside walls, spray polyurethane foam insulation, non-vented attic:
I need to use drywall clips for the corners and some other places.
Questions:
1) There appears to be 2 basic clip types. One screws to the framing, and the drywall just slips into a U shaped clip. The other requires a screw in both framing and drywall. The first seems like it would be simpler to use. Any advice on the best type to use.
2) Any particular manufacturers that stand out for quality/ease of use/or whatever?
3) My dry-waller has never used clips. It seems like a simple concept. Should I be concerned about being his first try at this? I assume following the manufacturer’s directions should be good enough. Any specific advice for a first time user?
4) The second floor is supported by either open web trusses, or 2X’s, and one large glulam beam. Since this is a non-vented (semi-conditioned) attic, is it accurate to assume that truss uplift is not an issue? And further, that special details for using drywall clips in these areas instead of just screwing the first-floor-ceiling drywall to the truss or beam are not applicable?
5) Should I use clips in all corners or just the exterior wall corners? Or maybe just where I’m missing the necessary dead wood to do otherwise? Some of the literature recommends extensive use of the clips to avoid drywall cracking. Do you concur?
6) HD Galvanized, plastic, zinc plated, plain steel?—-Does it matter?
7) If you are using sealant on exterior-wall drywall edges as a means to an air barrier, then doesn’t that negate the benefits of using clips as a means of preventing cracking of drywall in corners? i.e. if you tie it down with sealant, how is that any different than screwing it to the wall (as related to drywall corner cracking)? This doesn’t apply to me (spf is my seal), but I’m interested in this for furthering my education.
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Replies
We use the metal ones that screw to the top plate and wall corners before the sheetrockers arrive and that they can screw to or not as they choose depending on the order in which they hang the rock. I can't imagine why they would choose to hang a non-clipped side of a wall corner before the clipped side and certainly you would always finish hanging the ceiling before hanging the walls so the ceiling is held to the clips by the wall rock being pushed up from below.
We would never glue the edge of the ceiling drywall to the top plate as we generally glue or gasket (mostly gasket) the top of the wall drywall to the lower of the two top plates, (ie the top plate rather than the upper top -plate)
Typically wall to ceiling drywall cracks are caused by mid-winter roof truss uplift and the cure is to keep the hangers from attaching the drywall to the ceiling trusses within 16" of interior walls. the drywall is supported at the upper top plates with drywall clips or lumber blocking attached to the tops of the walls but not to the underside of the trusses so the trusses can lift without ripping out the corner tape.
As far as tips for a first time user I would not rely on the hanger to set the clips, go in and set them for him. You might even want to take a can of spray paint and spray the ceiling joists within 2' of interior walls and at obtuse angles at the "ridge" of scissor trusses and any other places where you might not want the drywall fastened to the framing to allow for uplift. If your layout places a truss parallel and close to an exterior wall then you would have to treat that as an interior wall as well. The hardest thing here is getting the hangers to stop attaching the drywall to the ceiling trusses where they are likely to lift in winter. the habit of nailing all the edges and screwing the centers later is pretty hard to break. The slide-in clips help make this more intuitive for them.
Michael, thanks for your response. I have a few follow-up questions/comments.
1) I will use metal clips and install them prior to the sheetrockers arrival. Will sheetrock the ceiling first.
2) Are the clips that you use just a backing (the drywall lays up against it), or do they have a retainer of some sort---like a small channel that the drywall edge fits into? i.e. one side screws to framing, and the other side has a small channel or some other shape to retain the drywall edge.
3) Do you use hot-dipped galvanized?
4) Can you refer me to a website for the ones you use or does your website protocol not allow that?
5) My question about gluing drywall edges was in reference to the walls. The question still stands.
6) In general, if you have a semi-conditioned attic (insulation at the roof rafters), then is it not true that the truss uplift issue goes away?
7) Is truss uplift less of a problem in a HH climate?
8) I think my original description of my basic framing construction was flawed. Let me try again-----
a) Stick built roof rafters
b) Ceiling joists / 2nd floor support is of two types. A portion of it is 16" tall floor trusses on 16" centers, supported on one end by an exterior wall and the other end by a large glulam beam (penetrating into the room by about 6"). The rest of the house uses 2 x 12's .
c) The only insulation I have is in the roof and the walls (plus some sound proofing between floors)
9) Considering my construction, do I still need to stay 16" away from the wall prior to screwing the drywall to the ceiling joists ?
10) Is it necessary to apply the same technique to interior walls as well as exterior walls?
11) What about the top of drywall walls sheets? Is it OK to screw them to the top plate or should I stay 16" down from the ceiling for the first screw?
12) Are there any GBA drawings or tutorials that address this in detail?
13) As a simplified rule of thumb, should I just stay 16" to 24" away from all corners (vertical or horizontal, interior or exterior) with drywall screws and call it done? And use clips in the corners.Except no clips on the top of wall sheets if they lay up against the top plate.
Michael,
Any thoughts on the above follow-up questions?